Railway signaling system.



H. A. WAGNER.

RAILWAY SIGNALING SYSTEM.

' APPLICATION FILED APR. 14, 1908.

l 1 87,473 Patented June 13, 1916.

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HERBERT A. WAGNER, OF SHORT HILLS, NEW JERSEY.

RAILWAY SIGNALING SYSTEM.

icense.

Application filed April 14, 1908.

To all whom it may concern:

Be it known that I, HERBERT A. WAGNER, a citizen of the United States, residing in Short Hills, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a specification.

My invention relates to electric railway signaling systems being specially adapted to systems for electric railways where it is desired that the rails of the track should form a return path for the traction current, while being used as circuits for signal controlling current. My invention is not, however, limited to this specific system and in using the term railway signaling system I include not only the ordinary arm or semaphore giving a visual indication at block entrances, but any device which is adapted to be controlled and thereby operate railway switches or give audible or visible indications to make the operation of a railway safe.

In such systems it is extremely desirable to employ conductively continuous rails in order to supply as perfect a return as possible for the traction current, as well as to avoid the well known difficulties attendant upon the insertion of insulation in the track, and it is one of the objects of my invention to provide a simple and effective system of this character in which the block ends may be limited with definiteness and in which there is no danger of a signal, being cleared, when a train is in the block protected by that signal, by current from an adjacent block.

To these ends my invention includes the supplying of the signal controlling current to the track from sources (preferably secondaries of transformers) which are in operative relation to the conductively continuous rails of the track, alternate sources being in reverse relation to the track (as by the employment of the transformer secondaries, alternate secondaries being oppositely connected to the rails). This causes a circuit to be normally established with two adjacent sources in series, this circuit being complete independently of the signal controlling devices to be described. The limit of a block may be taken as to the point between a pair of adjacent sources at which a zero difference of potential between the rails will normally be found. Thus with sources of equal strength and an intervening rail circuit of uniform impedance the point of zero differ- Specification of Letters Patent.

Patented June 13, 1916.

Serial No. 427,011.

ence of potential (assuming uniform track leakage) will be half way between the two transformers and this will be the dividing line between two blocks. The signal controlling electro-responsive devices (preferably relays having a fixed and a movable coil) are arranged in operative relation to the rails (preferably by having the movable coil of the relay supplied by the secondary of a transformer whose primary is connected across the rails) at some definite point between the block end and each source and as near the block end as practicable, so that normally a sufiicient current for the device will be derived from the rail circuit to operate the device. The direction of current in the electro-responsive device will depend upon the relative polarity of the adjacent source and the electro-responsive devices or relays are constructed and arranged so that when the train is in the block and short circuits the source for that block, the relay will not be affected to clear the signal by current from the adjoining block. This is because the current received by the relay from the adjoining block will be in a relatively opposite direction, and inasmuch as I have pro vided a relay having a fixed coil which receives a current always in fixed phase relatively to that of the source, relative reversal of the current in the movable coil will tend to produce a reverse movement of the relay to the same position as when it has no current. lVith such a system, however, the point of zero difference of potential cannot be definitely fixed by the mere connection of the sources to the track, but the normal point of Zero difference of potential is apt to shift and the point of zero difference of potential when a train is between adjacent sources is fixed by the train and moves with it. I therefore prefer to definitely fix the point of zero difference of potential by placing a bond to short circuit the rails at this point. When this is done no leakage currents or other causes can produce a departure from this definite point and therefore the block end is sharply limited by the bond. This bond is, of course, very desirable for the traction current and besides this it performs the function of maintaining a zero point of potential at that point even when there is a train in either of the blocks. Ordinarily, therefore, when this bond is introduced there can never be current from a source in one block passing through the relay coil of the adjacent blockwhen the train is in the latter block as would be the case if i.

no bond is provided. In'my preferred sys tem, therefore, the reverse connections of the sources in the blocks is normally without Y any effect upon the operation, the only effect produced being in case a bond should break.

I prefer that the bond shall be of low imparallel rails 2 and 3', each rail is electrically or conductively continuous from end to end; at separated. points along the track are 1 signals, like 8 and 25, these signals are auto- 'matically controlled as to their indication by the movement of a car on the track. The signal controlling current is preferably an alternating current. An alternating current generator 9 is connected with the supply circuit 8, 9; at separated points alternating current is supplied to the track through converters e, f, and h, the secondary coils of which, "13, r are connected in parallel branches between opposite rails 2 and 3 of the track, as shown. The primary coils 12 of the converters e and f are connected to the alternating circuit 8, 9, by conductors 10, 11, but the arrangement and connection of the two converters is such that they coincidently deliver to the rails impulses of opposite polarity, that is, when a positive impulse is delivered by e, a negative impulse is delivered by The signals 8 and t are shown as each directly operated by a local circuit 25, 26, 27, taking its current from the circuit 8, 9, although it is 'of no importance what means are employed to control the signals by the relays Z), c, d. This circuit is controlled by relays like Z), 0, consisting of fixed and'movalole coils. The fixed coils l9 and 21 are connected with the circuit 8, 9,

through conductors 23 and 24. The mom able coil 20 of relay 0 is in operative rela tion with the track through the medium of a transformer, the secondary coil 35 of which is included in circuit with the movable coil 20 and the primary coil of which 34 is ina cross wire or bridge between the ralls 2, 3. The relay 5 has its movable coil .22 in circuit with asimilar secondary coil 33, the primary coil 32 being in a cross wire between the rails 2 and 3. The arrangement of the relays (b and d is the same as that described with respect to relays c and Z). There, is a pair of, circuit closing points 28 and 29 controlled by the finger of the relay 5, and circuit closing points 30, 31, controlled by the finger of the relay 0. These I circuit closing points are in the local signal circuit 25, 26, 27, controlling the signal 8.

The relay (4 and the relay (Z have similar cirference of potential will normally be found. I

I definitely fix this point of Zero difference of potential by employing a bond as i0, 41,

to connect the rails at or about this point.

This bond consists of a section of conducting material of low impedance having its terminals connected to the two rails. A se ries of these bonds increases the efiiciency or the trackas a return circuit for the traction current and definitely establish the limits of the signaling current flow from the various 1 sources. 7

Tn'the drawing there are represented cars m and is, each having metal wheels connected by a metal axle which constitues a bridge of low resistance. The cars are supposed to be moving in the direction of the arrow.

The source of electricity f supplies two electrically independent circuits, one to the left and the other to the right of the source. This signal section between bonds 40 and 4:1 is clear and thesignal 8 stands at safety and the local operating circuits 25, 27, is closed at the relay circuit breaking points. The car m on the'signal section at the left forms a bridge acrossthe rails between the source 9 and the coil 34 excluding current from the coil. The circuit breaker of relay (4 opens the signal controlling circuit at the points 30, 31. The car is on the second signal section in advance, current from the source it is excluded from the coil 32 and the relay cl breaks its local signal operating circuit at 28, 29. If new the current from the source f could pass the point where the bond i1 is located and flow through the coil 32 and if'that current were of the proper polarity, the relay d would be operated to clear the signal despite the presence of the car 70 V in the block guarded by the signal, but the presence of the bond tl defines the point of zero difference of potential, and the current generated by source f cannot flow through the coil 32 in the section beyond the bond 41. If the bond 41 should not be provided or should it become broken by accident or otherwise, current from source 7 would flow in the coil 32, but I have arranged to guard against a false indication due to this con-- tingency by so connecting sources of alternating current that successive sources are of opposite polarity, and I have constructed the relays c and d so that each responds only to current of one relative polarity. It results from this that even if current from source f should get through to the signal circuit protecting car 7:: it would be ineffective to control the signal of that section. Addi tional sources of alternating current are connected to the track circuit as shown at it. The direct current generator 2' supplies the trolley wire and has its opposite pole connected to the track 8, 9, for the purposes of a return circuit.

It will be understood that I have described and diagrammatically illustrated a single specific embodiment of my invention in its preferred form, but that my invention is broader than such embodiment and I do not desire to be limited to the details thereof, but include within my invention modifications in the details and arrangement within the scope of the appended claims.

I'Vhat I claim as new and desire to secure by Letters Patent is 1. In a railway signaling system. a plurality of sources of signal controlling current, conductively continuous track rails ex tending between and reversely connected to successive sources, coils connected across the rails at intermediate points, signals and means, one for each coil, for affecting the operation of the signals responsively to the intensity and relative direction of the current in the coils.

2. In a railway signaling system, a series of sources of signal controlling current, conductively continuous track rails reversely connected to successive sources, coils connected across the rails at points intermediate said sources, signals, and means for aifecting the operation of each signal responsivcly to the intensity and relative direction of the current in the respective coils.

3. In a railway signaling system, a series of sources of signal controlling current, con-- ductively continuous track rails reversely connected to successive sources, means for definitely fixing along the rails intermediate successive sources points of Zero ditlerence of potential between the rails, coils connected across the rails between the sources and the adjacent points of Zero potential, signals, and means for affecting the signals responsively to the intensity and direction of current in the coils.

4;. In railway signaling system, two sources of signal controlling current, conductively continuous track rails extending between saic sources and reversely connected thereto, a bond connecting the rails and definitely fixing along the rails intermediate said sources a point of zero difference of potential between the rails, a coil connected across the rails between each source and the bond, two signals, and means for affecting the signals responsively to the intensity and direction of current in the respective coils 5. In a railway signaling system, the combination of a track consisting of two parallel electrically continuous rails, separated sources of signal controlling current connected across the track, the successive sources having terminals of opposite polarity, respectively, connected to the same rail,

signals at separated points along said track,

electro-responsive controlling devices for each signal in operative relation with. said track, and means whereby each device clears its signal responsive to effective current from one source while irresponsive to current from other sources.

6. In a railway signalin system, the combination of a track consisting of two parallel electrically continuous rails, separated sources of signal controlling current, successive sources having their terminals connected to opposite rails in series relation, means for establishing along the rails intermediate successive sources points or" substantially Zero difference of potential between the rails, signals at separated points along said tr ck, electro-responsive controlling devices for said signals connected to said track, and means whereby each device clears its signal responsive to effective current from one source and is irresponsive to current from the other adjacent source.

7. In a railway signaling system a series of sources of signal controlling current, conductively continuous track r ils reversely connected to alternate sources, signals, and coils operatively related to the respective signals to control the same and connected across the rails at points intermediate said sources and relatively near points of zero difference of potential between the rails.

8. In a railway signaling system, two sources of signal controlling current, conductively continuous track rails extending l'ie'tween said sources and reversely connected thereto, a bond connecting the rails and definitely fixing along the rails intermediate said sources point of Zero difference of potential between the rails, coils con nected across the rails at points at each side of and relatively near the bond, two signals, and means for afiecting the signals responsive to the intensity and direction of current in the respective coils.

9. In a railway signaling system, the combination of a track consisting of two parallel electrically continuous rails, separated sources of signal controlling current connected across the track, successive sources having terminals of opposite polarity, respectively, connected to the same rail, signals at separated points along said track, electro-responsive controlling devices for each signal in operative relation with said track at points relatively near its points of normal zero diiierence of potential, and means whereby each device clears its signal responsive to efi'ective current from one source while irr'esponsive to current from other sourcesi V 10. 1111a continuous rail block signaling system, rails which are conductively con tinuous for all currents, and sources of supply for signaling currents connected to the rails to produce points of equal potential in the two rails between the sources of supply, substantially as described.

11. In a continuous rail block signalin system, continuous track rails, sources of supply for signaling currents connected to the track rails, adjacent sources of supply being oppositely connected to the two rails to produce points of zero potential in the two rails between said sources of supply,

substantially as described. 7

1 In a block signaling system, sources of supply for signaling currents connected to the track rails, adjacent sources of supply being connected to the two rails, to produce points of neutral potential between such sources of supply, and conductors connecting the rails at the points of neutral potential, substantially as described.

13. In a railway signaling system, track rails, sources of signal controlling current, successive sources being reversely connected across the rails to produce along the rails between successive sources points of zero difference of potential between the rails which determine the extremities of block signaling sections, signals adjacent said points, a pair of coils receiving current from'the rails for determining thecontrol of the signals and connected for this purpose across the rails near each of said points of Zero diflerence of potential and remote from the sources, the coils of each pair being connected one on one side of the adjacent point of Zero difference of potential and one on the other side, and means receiving energy from said coilsfor determining the control of the signals responsive to cars passing from one section to another.

In testimony whereofll have signed my name to this specification, in the presence of two subscribing witnesses.

HERBERT A. l/VAGNER. Witnesses ANNA DALY, EDWIN Snenn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

